Semiconductor equipment

Abstract

A semiconductor device according to an aspect of the present disclosure comprises, on a substrate, a channel layer and a barrier layer in the stated order. The semiconductor device further comprises a gate electrode, a source electrode, and a drain electrode which are formed on the substrate with the channel layer and the barrier layer therebetween. The gate electrode, the source electrode, and the drain electrode are disposed so as to extend in a first direction. The channel layer or the barrier layer has, at a position facing the gate electrode, a plurality of interruption regions formed so as to be arranged side by side at prescribed intervals along the extension direction of the gate electrode. The interruption regions block flowing of electric current through the channel layer.

Description

Technical Field

[0001] The present disclosure relates to a semiconductor device.

Background Art

[0002] In the fifth-generation mobile communication system (5G), the use of signals in the millimeter-wave band is assumed. In the millimeter-wave band with large spatial attenuation, a high-power output is required, and high-output, high-frequency semiconductor devices are needed. Examples of high-output, high-frequency semiconductor devices include power amplifiers and RF switches (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] By the way, in high-output, high-frequency semiconductor devices, heat generation due to Joule heat becomes a problem. As the temperature of the channel rises, the electrical resistance of the channel and the surrounding wiring increases, and the device characteristics deteriorate. In particular, when the channels are dense, suppressing the concentration of heat generation leads to a decrease in the maximum temperature. Therefore, it is desirable to provide a semiconductor device capable of suppressing the concentration of heat generation.

[0005] The semiconductor device according to the first aspect of the present disclosure includes a channel layer and a barrier layer on a substrate in this order. This semiconductor device further includes a gate electrode, a source electrode, and a drain electrode formed on the substrate via the channel layer and the barrier layer. The gate electrode, the source electrode, and the drain electrode extend in a first direction. The channel layer or the barrier layer has a plurality of non-conducting regions formed side by side with a predetermined gap in the extending direction of the gate electrode at a position facing the gate electrode. The non-conducting regions inhibit the flow of current through the channel layer.

[0006] A semiconductor device according to a second aspect of the present disclosure comprises a channel layer and a barrier layer on a substrate in this order. The semiconductor device further comprises a plurality of gate electrodes, a plurality of source electrodes, and a plurality of drain electrodes formed on the substrate via the channel layer and the barrier layer. Each gate electrode, each source electrode, and each drain electrode extends in a first direction. The plurality of source electrodes and the plurality of drain electrodes are arranged alternately in a second direction intersecting the first direction. The plurality of gate electrodes are arranged one by one between the source electrodes and the drain electrodes. The channel layer or barrier layer has a plurality of non-passable regions formed opposite each gate electrode, aligned with a predetermined gap in the direction of extension of the gate electrode. The non-passable regions prevent current from flowing through the channel layer.

[0007] In the semiconductor device according to the first and second aspects of this disclosure, a plurality of non-passable regions are provided in the channel layer or barrier layer at a position facing the gate electrode, arranged in the direction of extension of the gate electrode with a predetermined gap between them. This makes it possible to reduce the current density in the direction of extension of the gate electrode compared to the case where no non-passable regions are provided. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an example of a planar configuration of a semiconductor device according to the first embodiment of this disclosure. [Figure 2] This figure shows an example of the cross-sectional configuration of the semiconductor device in Figure 1 along line AA. [Figure 3] This figure shows an example of the cross-sectional configuration of the semiconductor device at line BB in Figure 1. [Figure 4] This figure shows an example of the cross-sectional configuration of the semiconductor device along the CC line in Figure 1. [Figure 5] This figure shows an example of a planar configuration of a semiconductor device according to the second embodiment of this disclosure. [Figure 6] Figure 5 shows an example of the cross-sectional configuration of a semiconductor device along line AA. [Figure 7] Figure 5 shows an example of a cross-sectional configuration of a semiconductor device along the BB line. [Figure 8] It is a figure showing an example of a cross-sectional configuration along the C-C line of the semiconductor device of FIG. 5. [Figure 9] It is a figure showing a modified example of the cross-sectional configuration of FIG. 6. [Figure 10] It is a figure showing a modified example of the cross-sectional configuration of FIG. 8. [Figure 11] It is a figure showing a modified example of the cross-sectional configuration of FIG. 6. [Figure 12] It is a figure showing a modified example of the cross-sectional configuration of FIG. 8. [Figure 13] It is a figure showing a modified example of the cross-sectional configuration of FIG. 6. [Figure 14] It is a figure showing a modified example of the cross-sectional configuration of FIG. 8. [Figure 15] It is a figure showing a modified example of the planar configuration of FIG. 1. [Figure 16] It is a figure showing a modified example of the cross-sectional configuration of FIG. 2. [Figure 17] It is a figure showing a modified example of the cross-sectional configuration of FIG. 3. [Figure 18] It is a figure showing a modified example of the cross-sectional configuration of FIG. 4. [Figure 19] It is a figure showing a modified example of the planar configuration of FIG. 2. [Figure 20] It is a figure showing a modified example of the cross-sectional configuration of FIG. 3. [Figure 21] It is a figure showing a modified example of the cross-sectional configuration of FIG. 4. [Figure 22] It is a figure showing an example of the planar configuration of the semiconductor device according to the third embodiment of the present disclosure. [Figure 23] It is a figure showing a modified example of the planar configuration of FIG. 22. [Figure 24] It is a figure showing a modified example of the planar configuration of FIG. 22. [Figure 25] It is a figure showing a modified example of the planar configuration of FIG. 22. [Figure 26] It is a figure showing an example of a high-frequency module to which the semiconductor devices of FIGS. 1 to 25 are applied. [Figure 27] It is a figure showing an example of a wireless communication device to which the semiconductor devices of FIGS. 1 to 25 are applied.

Embodiments for Carrying Out the Invention

[0009] The following describes in detail the forms for implementing this disclosure with reference to the drawings. The following description is one specific example of this disclosure, and this disclosure is not limited to the following forms. Furthermore, this disclosure is not limited to the arrangement, dimensions, and dimensional ratios of each component shown in each drawing. The description will be given in the following order. 1. Background 2. First Embodiment (Semiconductor Device)...Figures 1-4 3. Second Embodiment (Semiconductor Device)...Figures 5-8 4. Modified example of the second embodiment (semiconductor device)...Figures 9 to 14 5. Modified example of the first embodiment (semiconductor device)...Figures 15-21 6. Third Embodiment (Semiconductor Device)...Figure 22 7. Modified example of the third embodiment (semiconductor device)...Figures 23-25 8. Application Examples (High-Frequency Modules, Wireless Communication Devices)...Figures 26, 27

[0010] <1. Background> Fifth-generation mobile communication systems (5G) are expected to utilize millimeter-wave signals. The millimeter-wave band, with its significant spatial attenuation, requires high power output, necessitating high-power, high-frequency semiconductor devices. Examples of such devices include power amplifiers and RF switches.

[0011] GaN possesses characteristics such as a high dielectric breakdown voltage, the ability to operate at high temperatures, and high saturation drift. The two-dimensional electron gas (2DEG) formed in GaN heterojunctions has high mobility and high sheet electron density. Due to these characteristics, high-electron-mobility transistors (HEMTs) using GaN heterojunctions can operate at low resistance, high speed, and high voltage. Therefore, high-electron-mobility transistors using GaN heterojunctions are expected to be applied to high-power, high-frequency semiconductor devices.

[0012] Incidentally, in power amplifiers, large currents flow through the channels, leading to heat generation due to Joule heating. As the channel temperature rises, the electrical resistance of the channel and surrounding wiring increases, degrading the power amplifier's characteristics. One way to suppress the temperature rise of the channels is to promote heat dissipation to the outside of the device. However, in mobile devices where GaN-based HEMTs are expected to be used, size constraints are significant, making it difficult to implement a sufficient heat dissipation mechanism.

[0013] Another effective way to suppress channel temperature rise is to reduce channel density. FETs for power amplifiers often employ a multi-finger structure with multiple gates in parallel. When the total gate width is constant, reducing the gate width per finger and increasing the number of fingers can suppress heat concentration and lower the maximum temperature. Furthermore, widening the spacing between fingers can further reduce the maximum temperature.

[0014] On the other hand, increasing the number of fingers and widening the finger spacing leads to an increase in device area. When the number of fingers is increased, the wiring area associated with the channel also increases, so even if the total gate length is the same, increasing the number of fingers results in a larger device area. In addition, the aspect ratio increases, which reduces the freedom of layout within the IC. Therefore, the following describes a semiconductor device with a multi-finger structure that can suppress the concentration of heat while keeping the size increase to a minimum, as well as embodiments of semiconductor modules and electronic devices equipped with such a semiconductor device.

[0015] <2. First Embodiment> [composition] Next, a semiconductor device 1 according to the first embodiment of this disclosure will be described. Figure 1 shows an example of a planar configuration of the semiconductor device 1 according to this embodiment. Figure 2 shows an example of a cross-sectional configuration of the semiconductor device 1 of Figure 1 along line AA. Figure 3 shows an example of a cross-sectional configuration of the semiconductor device 1 of Figure 1 along line BB. Figure 4 shows an example of a cross-sectional configuration of the semiconductor device 1 of Figure 1 along line CC.

[0016] Semiconductor device 1 is Al 1-x-y Ga x In y The semiconductor device 1 is equipped with a high electron mobility transistor using an N(0≦x<1,0≦y<1) / GaN heterojunction. In the semiconductor device 1, the high electron mobility transistor has a multi-finger structure in which multiple gates are arranged in parallel, for example. For example, the gate electrode 15, source electrode 17, and drain electrode 18 of the high electron mobility transistor extend in a first direction (left-right direction in the plane of Figure 1). Furthermore, for example, the source electrode 17 and drain electrode 18 are arranged to face each other via the gate electrode 15 in a second direction (up-down direction in the plane of Figure 1) that intersects the first direction.

[0017] The gate electrode 15 has a gate operating portion that contacts the channel layer 11 via a gate insulating film 14 and a barrier layer 12. This gate operating portion controls the current flowing in the portion of the channel layer 11 directly below the gate operating portion when a predetermined voltage is applied to the gate electrode 15. On the surface of the channel layer 11 on the side facing the gate operating portion, a plurality of impurity regions 11a are formed so as to traverse the gate operating portion in a second direction (vertical direction in the plane of Figure 1). The plurality of impurity regions 11a are arranged side by side in a first direction (horizontal direction in the plane of Figure 1) at predetermined intervals. The impurity regions 11a are inactive regions with high resistance to the channel layer 11, for example, by boron ion implantation. The portion of the channel layer 11 directly below the gate operating portion, where no impurity regions 11a are formed, is an active region. Furthermore, in the channel layer 11, an impurity region 11b, which is an inactive region with high resistance achieved by, for example, boron ion implantation, may be formed in the region facing both ends of the gate electrode 15, source electrode 17, and drain electrode 18 in a plan view. The impurity region 11b serves as an element isolation region. In the active region, a two-dimensional electron gas layer that forms a channel is generated. On the other hand, in the inactive impurity regions 11a and 11b, a two-dimensional electron gas layer is not generated. Thus, in this embodiment, a multi-finger structure is realized by dividing the active region (channel region) into multiple regions by multiple impurity regions 11a. The impurity regions 11a and 11b are formed collectively in the same process, for example, during the manufacturing process.

[0018] The semiconductor device 1, for example, comprises a channel layer 11 and a barrier layer 12 on a substrate 10 in that order. The semiconductor device 1 further comprises an insulating layer 13 on the barrier layer 12, for example, having an opening (hereinafter referred to as "gate opening") at the location where the gate operating part described above is formed. The gate opening extends in a first direction (left-right direction in the plane of Figure 1). The semiconductor device 1 further comprises a gate insulating film 14 formed in contact with the barrier layer 12, exposed on the bottom surface of the gate opening in the barrier layer 12. The gate insulating film 14 is a conformal layer formed to conform to the bottom surface and inner wall of the gate opening in the barrier layer 12, as well as the surface of the insulating layer 13. The semiconductor device 1 further comprises a gate electrode 15 formed to embed the gate opening in the barrier layer 12. The gate electrode 15 extends in a first direction (left-right direction in the plane of Figure 1). The semiconductor device 1 comprises the gate electrode 15 on the substrate 10 via the channel layer 11 and the barrier layer 12.

[0019] In addition to the gate opening, the barrier layer 12 has a pair of openings (hereinafter referred to as "source opening" and "drain opening") that extend in a first direction (left-right direction in the plane of Figure 1) at positions opposite to each other, flanking the gate opening. The channel layer 11 is exposed at the bottom surfaces of the source opening and the drain opening.

[0020] The semiconductor device 1 further includes, for example, a source electrode 17 that is ohmic-bonded to a channel layer 11 exposed on the bottom surface of the source aperture, and a drain electrode 18 that is ohmic-bonded to a channel layer 11 exposed on the bottom surface of the drain aperture. The source electrode 17 and the drain electrode 18 extend in a first direction (the left-right direction in the plane of the paper in Figure 1). The semiconductor device 1 has the source electrode 17 and the drain electrode 18 on the substrate 10 via the channel layer 11 and the barrier layer 12.

[0021] The surfaces of the source electrode 17 and the drain electrode 18 are covered by an insulating layer 13. Openings (hereinafter referred to as "extraction electrode openings") are formed in the insulating layer 13 and the gate insulating film 14, at the locations facing the source electrode 17 and the locations facing the drain electrode 18, respectively. The source electrode 17 is exposed at the bottom surface of one of the extraction electrode openings. The drain electrode 18 is exposed at the bottom surface of the other extraction electrode opening. The semiconductor device 1 further includes, for example, an insulating layer 16 formed in contact with the surfaces of the gate electrode 15 and the gate insulating film 14. The upper surface of the insulating layer 16 is a flat surface that is flattened compared to the surfaces of the gate electrode 15 and the gate insulating film 14. The insulating layer 16 has openings that communicate with the extraction electrode openings. The semiconductor device 1 further includes, for example, extraction electrodes 21 and 22 formed so as to fill the extraction electrode openings and the openings in the insulating layer 16. The extraction electrode 21 is in contact with the source electrode 17. The extraction electrode 22 is in contact with the drain electrode 18.

[0022] The substrate 10 is made of, for example, GaN. If a buffer layer for controlling the lattice constant is provided between the substrate 10 and the channel layer 11, the substrate 10 may be made of, for example, Si, SiC, sapphire, etc. In this case, the buffer layer is made of, for example, a compound semiconductor such as AlN, AlGaN, or GaN.

[0023] The channel layer 11 is the layer in which the channel of a high-electron-mobility transistor is formed. The active region (channel region) in the channel layer 11 is a region in which carriers are accumulated due to polarization with the barrier layer 12. The channel layer 11 is formed of a compound semiconductor material that readily accumulates carriers due to polarization with the barrier layer 12. For example, GaN can be used as such a compound semiconductor material. The channel layer 11 may also be formed of an undoped compound semiconductor material. In this case, impurity scattering of carriers in the channel layer 11 is suppressed, and carrier movement at high mobility is realized. The channel layer 11 is formed by a heterojunction of the channel layer 11 and the barrier layer 12, which are made of different compound semiconductor materials, thereby forming a two-dimensional electron gas layer that acts as a channel at the interface of the channel layer 11 in contact with the barrier layer 12.

[0024] The barrier layer 12 is formed of a compound semiconductor material that accumulates carriers in the channel layer 11 due to polarization with the channel layer 11. Examples of such compound semiconductor materials include Al 1-a-b Ga a In b One example is N(0≦a<1,0≦b<1). The barrier layer 12 may be formed of an undoped compound semiconductor material. In this case, impurity scattering of carriers in the channel layer 11 is suppressed, and carrier transport with high mobility is realized.

[0025] The insulating layer 13, gate insulating film 14, and insulating layer 16 are made of, for example, aluminum oxide (Al2O3), silicon oxide (SiO2), or silicon nitride (SiN). The gate electrode 15 is constructed by stacking nickel (Ni) and gold (Au) in that order from the substrate 10 side. The source electrode 17 and drain electrode 18 are configured to be ohmic-bonded to the channel layer 11 by stacking titanium (Ti), aluminum (Al), nickel (Ni), and gold (Au) in that order from the substrate 10 side.

[0026] [effect] Next, we will explain the effects in semiconductor device 1.

[0027] In semiconductor device 1, when a predetermined voltage is applied to the gate electrode 15, a two-dimensional electron gas layer is generated in the channel layer 11 where the impurity region 11a is not formed. As a result, the portion of the channel layer 11 where the impurity region 11a is not formed becomes the active region (channel region). Consequently, current flows from the drain electrode 18 to the source electrode 17 through the active region (channel region) of the channel layer 11. Therefore, the portion of the channel layer 11 where the impurity region 11a is not formed operates as a normal HEMT.

[0028] On the other hand, the portion of the channel layer 11 where the impurity region 11a is formed always becomes a non-pass region (a non-pass region that prevents current from flowing through the channel layer 11). By forming a non-pass region in the portion of the channel layer 11 facing the gate operating section in this way, the current density in the first direction (left-right direction in the plane of Figure 1) can be reduced compared to the case where no non-pass region is provided. As a result, the concentration of heat generated by the current is suppressed, and the maximum temperature in the channel can be reduced. Therefore, the degradation of device characteristics can be suppressed.

[0029] Furthermore, in this embodiment, by forming a non-passable region in the channel layer 11 opposite the gate operating section, the concentration of heat generated by the current is suppressed without widening the channel width, thereby reducing the maximum temperature in the channel. This makes it possible to suppress the concentration of heat while keeping the size of the semiconductor device 1 under control.

[0030] <3. Second Embodiment> Next, a semiconductor device 2 according to a second embodiment will be described. Figure 5 shows an example of a planar configuration of the semiconductor device 2 according to this embodiment. Figure 6 shows an example of a cross-sectional configuration of the semiconductor device 2 of Figure 5 along line AA. Figure 7 shows an example of a cross-sectional configuration of the semiconductor device 2 of Figure 5 along line BB. Figure 8 shows an example of a cross-sectional configuration of the semiconductor device 2 of Figure 5 along line CC.

[0031] In semiconductor device 2, instead of the impurity region 11a in semiconductor device 1, multiple openings 12a are provided in the barrier layer 12, thereby providing multiple non-passable regions in the channel layer 11 at the location facing the gate operating section. In other words, the channel layer 11 has openings 12a that penetrate the channel layer 11 as non-passable regions. Even in this case, similar to semiconductor device 1, the current density in the first direction (left-right direction in the plane of Figure 1) can be reduced compared to the case where no non-passable regions are provided. As a result, the concentration of heat generated by the current is suppressed, and the maximum temperature in the channel can be reduced. Therefore, the degradation of device characteristics can be suppressed.

[0032] Furthermore, in this embodiment, by forming a non-passable region in the channel layer 11 opposite the gate operating section, the concentration of heat generated by the current is suppressed without widening the channel width, thereby reducing the maximum temperature in the channel. This makes it possible to suppress the concentration of heat while keeping the size of the semiconductor device 2 under control.

[0033] <4. Modified Examples of the Second Embodiment> Next, a modified example of the semiconductor device 2 according to the second embodiment of this disclosure will be described.

[0034] [Variation 2-1] In the second embodiment described above, for example, as shown in Figures 9 and 10, the gate electrode 15 may have a columnar branch portion 15a that penetrates the channel layer 11 through the opening 12a. In this case, the branch portion 15a is in contact with the substrate 10 and the channel layer 11, for example, via the gate insulating film 14, and is insulated from the substrate 10. Figure 9 shows a modified example of the cross-sectional configuration of Figure 6. Figure 10 shows a modified example of the cross-sectional configuration of Figure 8.

[0035] At least the branched portion 15a of the gate electrode 15 may be made of a material with a higher thermal conductivity than the channel layer 11. This allows the heat generated in the channel to be propagated to the substrate 10 via the gate electrode 15. As a result, the heat dissipation of the semiconductor device 2 is improved, and the maximum temperature in the channel can be reduced. Therefore, the degradation of device characteristics can be suppressed.

[0036] [Modification 2-2] In the second embodiment described above, the semiconductor device 2 may further include a non-passable portion 25 that reaches the opening 12a of the barrier layer 12 from the back surface of the substrate 10, as shown in Figures 11 and 12. Figure 11 shows one modified example of the cross-sectional configuration of Figure 6. Figure 12 shows one modified example of the cross-sectional configuration of Figure 8.

[0037] The non-passable portion 25 is composed of, for example, an insulating layer 25b formed along the inner surface of a recess reaching the opening 12a of the barrier layer 12 from the back surface of the substrate 10, and a heat transfer portion 25a formed to fill the recess. The non-passable portion 25 is always a non-passable region (a non-passable region that inhibits the flow of current). The insulating layer 25b is composed of, for example, aluminum oxide (Al2O3), silicon oxide (SiO2), or silicon nitride (SiN). The heat transfer portion 25a may be composed of, for example, a material with a higher thermal conductivity than the thermal conductivity of the channel layer 11. This makes it possible to transfer the heat generated in the channel to the substrate 10 through the non-passable portion 25. As a result, the heat dissipation of the semiconductor device 2 is improved, and the maximum temperature in the channel can be reduced. Therefore, the degradation of device characteristics can be suppressed.

[0038] Furthermore, instead of the impurity region 11a, multiple non-conducting areas 25 are provided within the barrier layer 12 and the channel layer 11, resulting in a configuration where multiple non-conducting regions are provided in the channel layer 11 in the area facing the gate operating section. Even in this case, similar to semiconductor device 2, the current density in the first direction (left-right direction in the plane of Figure 1) can be reduced compared to the case where no non-conducting regions are provided. As a result, the concentration of heat generated by the current is suppressed, and the maximum temperature in the channel can be reduced. Therefore, the degradation of device characteristics can be suppressed.

[0039] [Modification 2-3] In the second embodiment described above, the semiconductor device 2 may further include an insulating portion 11c that penetrates the channel layer 11 from the opening 12a of the barrier layer 12, as shown in Figures 13 and 14. Figure 13 shows one modified example of the cross-sectional configuration of Figure 6. Figure 14 shows one modified example of the cross-sectional configuration of Figure 8.

[0040] The insulating portion 11c is composed of, for example, aluminum oxide (Al2O3), silicon oxide (SiO2), or silicon nitride (SiN). By providing multiple insulating portions 11c within the barrier layer 12 and channel layer 11 instead of the impurity region 11a, multiple non-passable regions (non-passable regions that inhibit current flow) are provided in the channel layer 11 at the location facing the gate operating portion. Even in this case, similar to semiconductor device 2, the current density in the first direction (left-right direction in the plane of Figure 1) can be reduced compared to the case where no non-passable regions are provided. As a result, the concentration of heat generated by the current is suppressed, and the maximum temperature in the channel can be reduced. Therefore, the degradation of device characteristics can be suppressed.

[0041] <5. Modified Examples of the First Embodiment> Next, a modified example of the first embodiment will be described.

[0042] Figure 15 shows an example of the planar configuration of the semiconductor device 1 according to this modified example. Figure 16 shows an example of the cross-sectional configuration of the semiconductor device 1 of Figure 15 along line AA. Figure 17 shows an example of the cross-sectional configuration of the semiconductor device 1 of Figure 15 along line BB. Figure 18 shows an example of the cross-sectional configuration of the semiconductor device 1 of Figure 15 along line CC.

[0043] In this modified example, trenches T are formed in each impurity region 11a, and each trench T penetrates the impurity region 11a, the barrier layer 12, the insulating layer 13, and the gate insulating film. The inner surface of each trench T is covered with the insulating layer 16. A metal portion 23, made of a metallic material (e.g., Cu, Au, etc.) with a higher thermal conductivity than the material of the channel layer 11, is inserted through each trench T. The metal portion 23 is in contact with the substrate 10 exposed at the bottom surface of the trench T. The metal portion 23 is further connected to, for example, a source electrode 17 or an extraction electrode 21.

[0044] In this modified example, the gate electrode 15 is divided into channel regions by providing trenches T and metal portions 23 in each impurity region 11a. In other words, the gate electrode 15 is composed of multiple partial gate electrodes, one for each channel region. In this modified example, the multiple partial gate electrodes are connected to each other by connecting wires 24 through through holes provided in the insulating layer 16.

[0045] As described above, in this modified example, the metal portion 23 penetrates each impurity region 11a and is in contact with the substrate 10, the source electrode 17, or the lead electrode 21. As a result, the heat generated in the channel region is propagated through each metal portion 23 to the substrate 10, the source electrode 17, or the lead electrode 21, and discharged to the outside. Therefore, compared to the case where the metal portion 23 is not provided, the current density can be reduced in both the first direction (left-right direction in the plane of Figure 1) and the second direction (up-down direction in the plane of Figure 1). As a result, the concentration of heat generated by the current is suppressed, and the maximum temperature in the channel can be reduced. Consequently, the degradation of device characteristics can be suppressed.

[0046] Figures 19, 20, and 21 show examples of cross-sectional configurations of the semiconductor device 1 according to this modified example. Figure 19 shows an example of the cross-sectional configuration at the location corresponding to line AA in Figure 1. Figure 20 shows an example of the cross-sectional configuration at the location corresponding to line BB in Figure 1. Figure 21 shows an example of the cross-sectional configuration at the location corresponding to line CC in Figure 1.

[0047] In this modified example, a back barrier layer 26 is provided within the channel layer 11. The back barrier layer 26 performs quantum confinement of the two-dimensional electron gas (2DEG) formed in the channel layer 11. The back barrier layer 26 is made of, for example, AlGaN. The thermal conductivity of the back barrier layer 26 is low. Therefore, the thermal resistance at the interface of the back barrier layer 26 worsens the heat dissipation performance. However, since multiple impurity regions 11a are provided in the channel layer 11, the maximum temperature can be reduced, and performance degradation due to heat generation can be prevented.

[0048] <6. Third Embodiment> Next, a semiconductor device 3 according to a third embodiment of this disclosure will be described. Figure 22 shows an example of a planar configuration of the semiconductor device 3 according to this embodiment.

[0049] Semiconductor device 3 corresponds to semiconductor devices 1 and 2 with multiple high-electron-mobility transistors. In semiconductor device 3, each high-electron-mobility transistor has, for example, a multi-finger structure in which multiple gates are arranged in parallel. Furthermore, the source electrode 17 or drain electrode 18 is shared between two adjacent high-electron-mobility transistors.

[0050] The semiconductor device 3, for example, comprises a channel layer 11 and a barrier layer 12 on a substrate 10 in that order. The semiconductor device 3 further comprises, for example, a plurality of gate electrodes 15, a plurality of source electrodes 17, and a plurality of drain electrodes 18 on the substrate 10 via the channel layer 11 and the barrier layer 12. Each gate electrode 15, each source electrode 17, and each drain electrode 18 extends in a first direction (left-right direction in the plane of Figure 22). The plurality of source electrodes 17 and the plurality of drain electrodes 18 are arranged alternately in a second direction (up-down direction in the plane of Figure 22) intersecting the first direction. Each of the plurality of gate electrodes 15 is arranged one at a time between the source electrodes 17 and the drain electrodes 18.

[0051] In this embodiment, a plurality of impurity regions 11a are provided at positions facing each gate electrode 15, arranged in the extending direction of the gate electrode 15 with a predetermined gap between them. The plurality of impurity regions 11a are arranged, for example, in a matrix in a plan view. Furthermore, a plurality of regions of the channel layer 11 in which no impurity regions 11a are formed (active regions (channel regions)) are also arranged in a matrix in a plan view. As a result, by forming a non-passable region (impurity region 11a) in the channel layer 11 at the location facing the gate operating part, the current density in both the first and second directions can be reduced compared to the case in which no non-passable region (impurity region 11a) is provided. Consequently, the concentration of heat generated by the current is suppressed, and the maximum temperature in the channel can be reduced. Therefore, the degradation of device characteristics can be suppressed.

[0052] <7. Modified Examples of the Third Embodiment> Next, a modified example of the semiconductor device 3 according to the third embodiment of this disclosure will be described.

[0053] [Modification 3-1] In the third embodiment described above, the multiple impurity regions 11a may be arranged alternately in both the row and column directions in a plan view, for example, as shown in Figure 23. In this case, the multiple impurity regions 11a are positioned so as not to face each other via the source electrode 17 or the drain electrode 18. In this case, compared to the third embodiment described above, the distance between two adjacent impurity regions 11a in the second direction can be increased. This suppresses the concentration of heat generated by the current and reduces the maximum temperature in the channel. Therefore, degradation of device characteristics can be suppressed.

[0054] [Modification 3-2] In the third embodiment described above, the region in which the plurality of impurity regions 11a are formed is denoted as α. The plurality of impurity regions 11a may be formed relatively wider in the second direction in the central part of region α in the extending direction (second direction) of the source electrode 17 and the drain electrode 18, as shown in Figure 24, and relatively narrower in the second direction at both ends of region α in the second direction. In this case, the width in the second direction of the impurity regions 11a provided at both ends of region α in the second direction is denoted as L1. The width in the second direction of the impurity region 11a provided in the center of region α is denoted as L3. The width in the second direction of the impurity region 11a provided between the impurity region 11a with width L1 and the impurity region 11a with width L3 in region α is denoted as L2. In this case, widths L1, L2, and L3 satisfy the following equations. L3>L2>L1

[0055] In this case, the current density in the second direction can be reduced compared to when all impurity regions 11a are formed to be of equal size. As a result, the concentration of heat generated by the current is suppressed, and the maximum temperature in the channel can be reduced. Therefore, the degradation of device characteristics can be suppressed.

[0056] [Modified example 3-3] In the modified example 3-3 described above, in the central portion of the second direction, multiple impurity regions 11a may be formed not only directly beneath the gate electrode 15 of the channel layer 11, but also directly beneath the drain electrode 18 or the source electrode 17. In this case, multiple high-electron-mobility transistors provided in the central portion of the second direction may share one impurity region 11a with each other. In this case, the current density in both the first and second directions can be reduced compared to the case where all impurity regions 11a are formed only directly beneath the gate electrode 15. As a result, the concentration of heat generated by the current is suppressed, and the maximum temperature in the channel can be reduced. Therefore, the degradation of device characteristics can be suppressed.

[0057] <8. Examples of Application> [Application Example 1] Next, with reference to Figure 26, a high-frequency module 4 to which semiconductor devices 1, 2, and 3 according to each embodiment and modified example of the present disclosure are applied will be described. Figure 26 is a perspective view of the high-frequency module 4.

[0058] The high-frequency module 4 includes, for example, an edge antenna 42, a driver 43, a phase adjustment circuit 44, a switch 41, a low-noise amplifier 45, a bandpass filter 46, and a power amplifier 47.

[0059] The high-frequency module 4 is an antenna-integrated module in which an array-shaped edge antenna 42 and front-end components such as a switch 41, a low-noise amplifier 45, a bandpass filter 46, and a power amplifier 47 are integrated and mounted as a single module. Such a high-frequency module 4 can be used, for example, as a transceiver for communications. The transistors that make up the switch 41, low-noise amplifier 45, power amplifier 47, etc., provided in the high-frequency module 4 may be composed of high-electron-mobility transistors, for example, those provided in semiconductor devices 1, 2, 3 according to each embodiment and its modifications in this disclosure, in order to increase the gain at high frequencies.

[0060] [Application Example 2] Figure 27 shows an example of a wireless communication device. This wireless communication device is a multi-functional mobile phone system, such as a voice communication, data communication, and LAN connection system. The wireless communication device includes, for example, an antenna ANT, an antenna switch circuit 5, a high-power amplifier HPA, a high-frequency integrated circuit RFIC (Radio Frequency Integrated Circuit), a baseband section BB, an audio output section MIC, a data output section DT, and an interface section I / F (for example, wireless LAN (W-LAN; Wireless Local Area Network), Bluetooth®, etc.). The antenna switch circuit 5 is configured to include a high electron-mobility transistor provided in a semiconductor device 1 according to one embodiment of this disclosure and its modifications. The high-frequency integrated circuit RFIC and the baseband section BB are connected by the interface section I / F.

[0061] In a wireless communication device, during transmission, that is, when the transmission signal is output from the transmission system of the wireless communication device to the antenna ANT, the transmission signal output from the baseband section BB is output to the antenna ANT via a high-frequency integrated circuit (RFIC), a high-power amplifier (HPA), and an antenna switch circuit 5.

[0062] During reception, that is, when the signal received by the antenna ANT is input to the receiving system of the wireless communication device, the received signal is input to the baseband section BB via the antenna switch circuit 5 and the high-frequency integrated circuit RFIC. The signal processed by the baseband section BB is output from output sections such as the audio output section MIC, the data output section DT, and the interface section I / F.

[0063] The present disclosure has been described above with reference to embodiments, modifications, and application examples, but the present disclosure is not limited to the above embodiments, and various modifications are possible. The effects described herein are merely illustrative. The effects of the present disclosure are not limited to those described herein. The present disclosure may have effects other than those described herein.

[0064] Furthermore, for example, this disclosure can take the following configuration. (1) The substrate is provided with a channel layer and a barrier layer in this order, and a gate electrode, source electrode, and drain electrode are formed on the substrate via the channel layer and the barrier layer and extend in a first direction. The channel layer or the barrier layer has a plurality of non-passable regions formed opposite the gate electrode, arranged in the direction of extension of the gate electrode with a predetermined gap between them, which obstruct the flow of current through the channel layer. Semiconductor equipment. (2) The channel layer has the non-communicating region, The aforementioned non-passable region is formed by ion implantation into the channel layer. (1) The semiconductor device described above. (3) The channel layer has an element isolation region in a plan view of the channel layer that faces both ends of the gate electrode, the source electrode, and the drain electrode. The aforementioned non-passable region and the aforementioned element isolation region were formed collectively in the same process during the manufacturing process. (2) Semiconductor device as described above. (4) The metal portion further penetrates the aforementioned non-passable region and the barrier layer and is connected to the source electrode. The semiconductor device described in (2) or (3). (5) The barrier layer has the impassable region, The barrier layer has an opening that penetrates the barrier layer, which constitutes the non-passable region. (1) The semiconductor device described above. (6) The gate electrode has a branch portion that penetrates the channel layer through the opening. (5) Semiconductor device as described above. (7) The branched portion is made of a material with a higher thermal conductivity than the channel layer. (6) Semiconductor device as described above. (8) The substrate further includes a non-conducting portion that reaches the opening from the back surface of the substrate and obstructs the flow of current through the channel layer. (5) Semiconductor device as described above. (9) The non-conducting portion has a heat-transmitting section made of a material with a higher thermal conductivity than the thermal conductivity of the channel layer. (8) Semiconductor device as described above. (10) The channel layer further comprises a back barrier layer that performs quantum confinement of the two-dimensional electron gas formed in the channel layer. A semiconductor device as described in any one of (1) through (9). (11) The substrate is provided with a channel layer and a barrier layer in this order, and is provided with a plurality of gate electrodes, a plurality of source electrodes and a plurality of drain electrodes formed on the substrate via the channel layer and the barrier layer and extending in a first direction, The plurality of source electrodes and the plurality of drain electrodes are arranged alternately in a second direction intersecting the first direction, and the plurality of gate electrodes are arranged one by one between the source electrodes and the drain electrodes. The channel layer or the barrier layer has a plurality of non-passable regions formed at positions opposite each gate electrode, with predetermined gaps between them in the direction extending of the gate electrode, which prevent current from flowing through the channel layer. Semiconductor equipment. (12) The aforementioned multiple non-passing regions are positioned at locations that are not directly opposite each other via the source electrode or the drain electrode. The semiconductor device described in (11). (13) The aforementioned multiple impassable regions are formed such that, in the central portion of the region where the multiple impassable regions are formed, they are relatively wider in the first direction, and in the end portions of the region where the multiple impassable regions are formed, they are relatively narrower in the first direction. (11) Semiconductor device as described above.

[0065] This application claims priority based on Japanese Patent Application No. 2021-077976, filed with the Japan Patent Office on 30 April 2021, and all contents of that application are incorporated herein by reference.

[0066] Those skilled in the art will understand that various modifications, combinations, subcombinations, and changes can be conceived depending on design requirements and other factors, and that these fall within the scope of the attached claims and their equivalents.

Claims

1. The substrate is provided with a channel layer and a barrier layer in this order, and a gate electrode, source electrode, and drain electrode are formed on the substrate via the channel layer and the barrier layer and extend in a first direction. The channel layer or the barrier layer has a plurality of non-passable regions formed opposite the gate electrode, arranged in the direction of extension of the gate electrode with a predetermined gap between them, which obstruct the flow of current through the channel layer. The channel layer has the non-communicating region, The aforementioned non-passable region is formed by ion implantation into the channel layer, The channel layer has an element isolation region in a plan view of the channel layer that faces both ends of the gate electrode, the source electrode, and the drain electrode. The aforementioned non-passable region and the aforementioned element isolation region were formed collectively in the same process during the manufacturing process. Semiconductor equipment.

2. A semiconductor device comprising a channel layer and a barrier layer on a substrate in this order, and a gate electrode, a source electrode and a drain electrode formed on the substrate via the channel layer and the barrier layer and extending in a first direction, The channel layer or the barrier layer has a plurality of non-passable regions formed opposite the gate electrode, arranged in the direction of extension of the gate electrode with a predetermined gap between them, which obstruct the flow of current through the channel layer. The channel layer has the non-communicating region, The aforementioned non-passable region is formed by ion implantation into the channel layer, The semiconductor device further comprises a metal portion that penetrates the non-passable region and the barrier layer and is connected to the source electrode. Semiconductor equipment.

3. A semiconductor device comprising a channel layer and a barrier layer on a substrate in this order, and a gate electrode, a source electrode and a drain electrode formed on the substrate via the channel layer and the barrier layer and extending in a first direction, The channel layer or the barrier layer has a plurality of non-passable regions formed opposite the gate electrode, arranged in the direction of extension of the gate electrode with a predetermined gap between them, which obstruct the flow of current through the channel layer. The barrier layer has the impassable region, The barrier layer has an opening that penetrates the barrier layer, which constitutes the impassable region. The semiconductor device further includes a non-conducting portion that extends from the back surface of the substrate to the opening and obstructs the flow of current to the channel layer. Semiconductor equipment.

4. The gate electrode has a branch portion that penetrates the channel layer through the opening. The semiconductor device according to claim 3.

5. The branched portion is made of a material with a higher thermal conductivity than the channel layer. The semiconductor device according to claim 4.

6. The non-conducting portion has a heat-transmitting section made of a material with a higher thermal conductivity than the thermal conductivity of the channel layer. The semiconductor device according to claim 3.

7. The channel layer further comprises a back barrier layer that performs quantum confinement of the two-dimensional electron gas formed in the channel layer. A semiconductor device according to any one of claims 1 to 6.

8. The substrate is provided with a channel layer and a barrier layer in this order, and is provided with a plurality of gate electrodes, a plurality of source electrodes and a plurality of drain electrodes formed on the substrate via the channel layer and the barrier layer and extending in a first direction, The plurality of source electrodes and the plurality of drain electrodes are arranged alternately in a second direction intersecting the first direction. The plurality of gate electrodes are arranged one by one between the source electrode and the drain electrode, The channel layer or the barrier layer has a plurality of non-passable regions formed at positions opposite each gate electrode, with predetermined gaps between them in the direction extending of the gate electrode, which obstruct the flow of current through the channel layer. The aforementioned multiple non-passing regions are positioned at locations that are not directly opposite each other via the source electrode or the drain electrode. Semiconductor equipment.

9. A substrate comprising a channel layer and a barrier layer in this order, and comprising a plurality of gate electrodes, a plurality of source electrodes and a plurality of drain electrodes formed on the substrate via the channel layer and the barrier layer and extending in a first direction, The plurality of source electrodes and the plurality of drain electrodes are arranged alternately in a second direction intersecting the first direction. The plurality of gate electrodes are arranged one by one between the source electrode and the drain electrode, The channel layer or the barrier layer has a plurality of non-passable regions formed at positions opposite each gate electrode, with predetermined gaps between them in the direction extending of the gate electrode, which obstruct the flow of current through the channel layer. The aforementioned multiple impassable regions are formed such that, in the central portion of the region where the multiple impassable regions are formed, they are relatively wider in the first direction, and in the end portions of the region where the multiple impassable regions are formed, they are relatively narrower in the first direction. Semiconductor equipment.

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